


PUSH (me) OVER (the edge)

by OverexcitedDragon



Category: Haikyuu!!
Genre: Bottom Miya Osamu, Choking, Condom denial, Creampie, Fucked Stupid, M/M, Mildly Dubious Consent, Sibling Incest, Top Miya Atsumu, Twincest, Verbal Humiliation, atsumu is just pushy and osamu is a pushover, idk why thats so hot to me that i ended up putting it in two fanfics, very mild, very quick mentions of fisting
Language: English
Status: Completed
Published: 2021-01-19
Updated: 2021-01-19
Packaged: 2021-03-17 14:09:00
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,237
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28850361
Author URL: https://archiveofourown.org/users/OverexcitedDragon/pseuds/OverexcitedDragon
Summary: Osamu's bunk bed was almost always perfectly made in the mornings.Atsumu's bunk bed, on the other hand, was almost always a chaos of questionable stains and messy sheets.
Relationships: Miya Atsumu/Miya Osamu
Comments: 39
Kudos: 360
Collections: MiyaTwins





	PUSH (me) OVER (the edge)

**Author's Note:**

> i shat this out in 2 hours at midnight on a work night!! my arms hurt like ass but i am horny and i want the twins to fuck HAVE FUN!! sorry its not beta'd but i hope it's palatable at least
> 
> (EDIT: I made some dialogue edits to fit the way the brothers actually call each other plus the badly translated Kansaiben LMAO I wrote this immediately after meeting them in the anime so their verbal dynamic still hadn't dawned on me)

It was rare for them to sleep alone, ever since they were young. Nights were a mess of tangled limbs, wrapped together so tight half the bed was empty, even when the mattress was small on the bottom bunk.

When their parents asked, Osamu blamed it on the stifling upper bunk, while Atsumu made a show of never giving away his lower bed.

They learned not to ask, after a while.

But the siblings knew they probably listened, at times. They just didn’t care if they were heard.

Atsumu especially.

“Yer so pretty, look at you,” he’d coo, a deranged smile plastered onto his lips as he held his brother close, dipped a hand under the waistband of his underwear. “So handsome, where did ‘ya get your looks?”

“Funny.”

It wasn’t, it never was, but Atsumu entertained himself, be it with praising his brother or making him moan, and Osamu didn’t care as long as it felt good.

And, gods, Atsumu always made it feel _good_.

He kissed like a hungry man and touched like a blind one, like it was important to memorize the dips and curves of Osamu’s body. Every muscle, every corner, every bead of sweat and every strand of hair— nothing was safe from Atsumu’s touches. A lesser man would think him desperate, but Osamu knew better; he was just good at it. It was really that simple.

“Lemme fuck you tonight, 'Samu?” He whispered. Or tried. Atsumu always seemed physically unable to lower his tone.

“Only if you wear a condom.”

“Nah.”

“ _Atsumu_.”

He licked Osamu’s neck, wiped off his sweat only to coat his skin with a layer of spit. Filthy, as always. But something about it never bothered him; it always seemed like his brother set every action perfectly, only to culminate into the most back breaking orgasm he’d ever had.

“I like filling ya up,” Atsumu murmured, bit his ear and licked inside, like a filthy old man. All while taking hold of his brother’s cock, rubbing a thumb over the tip just the way he knew Osamu liked. “I like staining yer underwear.”

“Yer disgusting.”

“Ya like it, too.”

“Shut up.”

“Ya _like it_ ,” he chuckled, squeezing the tip of Osamu’s cock _just_ right, the bastard. “You like it when I fuck you stupid, when I creampie yer ass. _C’mon_ , baby bro.”

“Don’t call me that.”

It was useless telling Atsumu to do or not do anything. As absurd as it would be, Osamu genuinely suspected that telling his brother the opposite of what he wanted would be effective.

Atsumu’s hand moved quickly, fisting his brother’s cock hard and _just_ this side of too tight, just enough to make him wonder if it hurt or just felt _way_ too good. And it was precisely the way he liked, too, because of course it was, twisting up and down just the very tip, rubbing the precum to smooth Atsumu’s calloused fingers over the sensitive skin of Osamu’s cock.

“I’m gonna cum inside ya,” he threatened, so excited about his absurd fantasies he let out a full body giggle. “I’m gonna make you cry, baby brother.”

“You’re the fucking worst.”

“Hold that thought.”

Atsumu shuffled down, pulling Osamu’s boxers off with practiced speed, and almost immediately wrapped his lips around his brother’s cock, throat deep and swallowing down every inch. Osamu nearly came right then and there, body twitching and eyes rolling back with the pressure of the man’s throat around him.

“You _freak_ —”

His brother laughed, which made the idiot choke on Osamu’s cock, and he pulled out to have a minute long coughing fit.

“Yer an idiot.”

“I was doing such a good job, too,” Atsumu murmured, red faced. His hand was still wrapped around his brother’s cock like it was some comfort device. The absolute moron.

“Well, no one said ya had to stop.”

Ah, there it was, the _one_ half-hearted praise Osamu allowed himself. And it was enough, too, brought a smirk to Atsumu’s lips, made his brother shiver in excitement.

One time he had actually allowed himself to praise him properly, some _you’re doing so good_ kind of bullshit. Best sex of his life, but _worst_ night of teasing he ever had. Osamu swore to himself never to praise Atsumu again, his head was big enough as it was.

He watched his brother descend on his cock with an almost innocent excitement, drooling and sucking like a desperate man. It felt _amazing_ , but gods it was _embarrassing_.

“Yer too nois—”

 _Fucker_.

He felt the dull ache before he even noticed the finger sliding into him, like Atsumu had somehow found a way to sneak inside him unnoticed.

He wondered forlornly how loose he actually was because of his sex obsessed brother.

“S’been so easy to slip inside you,” Atsumu provided, ever so helpful. “Bet I can fit m' whole fist in there.”

“ _Please_ , don’t.”

“Next time?”

“ _Do not_.”

“Ye’d feel so _good_ , though.”

It had been a lost battle before it even started, Osamu knew it. He sighed, _guess I’m getting fisted tomorrow_. A problem for future Osamu.

Atsumu, on the other hand, seemed more excited than ever. He spat a fat, disgusting glob of saliva onto his fingers, slipping them back into his brother. It felt good, there was little stretch, just tight enough, Osamu wondered how many there were.

“See? I can fit four already.”

Osamu also wondered when his brother was going to shut up.

“Don’t announce it.”

“S' _hot_.”

“Not to me.”

“This isn’t just about _you_.” Atsumu blew raspberries at him, and then immediately descended his putrid mouth over his brother’s cock again, swallowing him to the hilt the same moment his fingers brutally rubbed against Osamu’s prostate.

Well. _Well_.

He didn’t even have time to warn his brother.

Osamu’s back arched violently with the force of his orgasm, and, _curse him_ , he moaned loud, long, high pitched and _begging_ as he spilled into Atsumu’s throat.

When he recovered from the frankly _absurd_ overreaction of his body, he was faced with the nightmarish sight of his brother’s smile, licking his lips clean.

“Didn’t even warn me.”

“I didn’t have time…” it came out as a plea. Pathetic, but his accursed body wouldn’t give back the reins, arching and shivering for more.

“Guess I gotta punish ya.”

“Jesus, ' _Tsumu_ …” he groaned. “Fine, _fine_. You can fuck me without a condom.”

His brother smiled, all teeth and raised eyebrows, like he never intended to do anything else in the first place.

“I got a thumb in too, by the way.”

“ _I hate you_.”

“Don’t worry,” Atsumu licked his lips, focused on lining himself up just right, pressing against Osamu’s twitching hole. “Bet yer still tight enough for my cock.”

It was all the warning he got before he was stuffed full of his brother, down to the hilt, bulging out his stomach in a way that should freak him out but just made him wail _louder_. His heartbeat drummed loudly in his ears, but Osamu could still hear himself calling Atsumu’s name, desperate, _begging_.

“ _Please, please, fuck—_ ”

“There ya go.”

“ _Atsumu, fuck, fuckfuckfuck…_ ”

“See? Told ya, still tight enough. 'M gonna move.”

Osamu was sure he could feel his brain leaking out his ears. He stared hard at the bump in his stomach, feeling the pressure of Atsumu’s cock threatening to push his dinner back out. _Christ_. They’ve always been the same size, length and girth, but Atsumu always _felt_ like a goddamn monster compared to him.

“Please…” Osamu murmured, clutching at the blankets. “Pleas— _aaaahnnnn_ …!”

It felt like heaven and hell all at once, tugging Osamu at the seams, pulling him apart and making him lose his mind a little more with each thrust, each push, each filthy praise coming out Atsumu’s mouth that sounded just enough like actual words to make Osamu sob.

“God, yer so fucking hot like this,” Atsumu chuckled. “Always gets to me how stupid you get when I fuck ya…”

“ _Hnn, noo… stop…_ ”

“No? _No?_ ”

Atsumu leaned over him with a toothy grin, wrapping his fingers _tight_ around Osamu’s waist and looking straight into his brother’s eyes with near murderous intent. He licked a wet stripe from Osamu’s chin to his cheek, ending with a loud smacked kiss against his temple, lips ghosting over the sweat glistened skin.

And buried himself so deep into his brother Osamu felt like he was about to vomit.

“Tell me _no_ one more time, ya fucking whore.”

Osamu clenched his jaw. Everything in his head told him to hate this, yell at Atsumu, push him away, _how dare you talk to me like that_ … but all that happened was a sobbed moan, and his legs wrapping around his brother’s waist.

The _fucker_.

“C’mon, tell me _no_ ,” Atsumu murmured, and there was a smile in his tone as he started fucking Osamu again, thrusting fast and violent as his brother whimpered desperately. “Tell me to stop fucking ya. You can’t, right?”

“ _Tsumu…_ ”

“Yer so fucking messy.”

“ _Hnng… please, fuck…_ ”

“You act all tough, but you love this so much.”

“ _Fuck, Christ, Tsumu, pleaseplease…_ ”

Osamu moaned pathetically when his brother kissed him. Deep, wet, _filthy_ , teeth clacking and drool spilling down his cheeks. Atsumu was an awful kisser, but he kissed the same way he fucked— he took, and took, and _took_ until there was nothing left of Osamu, licking deep into his mouth until he choked and biting down on his lips until they ached. Every time it felt like he was being assaulted.

“So fucking filthy,” Atsumu chuckled into the kiss, hands shifting upwards, over Osamu’s abdomen, his chest, and finally wrapping tight against his neck. “Beg.”

“ _Pleas—hhhnnn…_ ”

It was hard to breathe, hard to think or feel anything that wasn’t _Atsumu_ , the bastard, the disgusting, ridiculous, filthy—

“Please, what? Beg for me, 'Samu, c’mon,” he licked his brother’s other cheek obscenely. “You know I like it when ya beg me to cum inside…”

“Plea— _please, fuck, fuck_ …”

“Do it before I knock you the fuck out.”

 _Oh_ , it hit him like a damn bullet. Osamu felt his whole body spasm as yet another orgasm flooded him, turned his brain to cotton and made his voice come out in the most pathetic wail known to man.

“Oh, _shit_ , baby brother,” Atsumu groaned. Even in his fog, Osamu noted how pretty he sounded when he actually moaned. “You’re so tight, fuck, fuck, c’mon, baby, beg for me, _beg pretty for me…_ ”

 _Gods_.

Osamu wrapped his arms around Atsumu’s neck, a gesture that contrasted absurdly with the fingers still wrapped around his own. He looked into his disgusting brother’s eyes and licked his lips. “'Tsumu, _hnn_ … please cum inside me… I want it, please, _please_ ruin me…”

The manic grin on Atsumu’s lips made him flinch.

“Fuck, 'Samu, _baby_ , ya sound so fucking pretty when you beg…”

If Atsumu was fucking him hard before, now he was positively _pounding_ his brother into the bed. He had finally released Osamu’s neck only to grab onto the headboard and fuck him like a damn beast in rut. The wood creaked, the legs squeaked against the floor, the headboards hit the wall; it was as if an animal had taken over Atsumu. The bastard, the _perfect bastard_ with his _perfect cock_.

Their parents were absolutely hearing it, too, there was _no_ doubt, yet it just seemed to rile him up more.

“Such a pretty little whore for me,” he growled into Osamu’s ear, all teeth and spit, completely gone. “Bet ya like it when we’re loud, _fuck_ , bet you like it when I make you cry, _'S_ _amu, fuck, fuck—_ ”

When he finally came, Atsumu bit down hard on his brother’s shoulder, snarling like a dog as he fucked him almost desperately. Osamu felt it fill him up, stuff him full of _Atsumu_ , so much he heard it squelching with each thrust of his brother’s hips, cursing softly at the knowledge that it would stain the sheets.

At least they weren’t his sheets.

When Atsumu finally relaxed after his orgasm, their ragged breathing was all that filled the room for a long moment. Osamu gently stroke his brother’s hair, but his patience ran thin when the aches finally took over the waning adrenaline.

“Yer heavy, ya stink, yer gross, get off me,” he groaned.

“You sound so much cuter during sex.”

“Tough.”

Atsumu rolled over with a chuckle and a sigh, sounding a lot more composed, more _human_ now.

“Wanna clean up?”

“No,” Osamu winced. “I don’t wanna risk running into anyone.”

His brother laughed, a loud, obnoxious full belly laughter. And Osamu wanted to be pissed at him, but he couldn’t help the gentle warmth that washed over him at the sound of Atsumu’s laughter.

Hearing it felt like watching a summer sunset.

“Yer staring,” Atsumu grinned.

“Am not.”

“Are too.”

“Am n—”

 _Unfair_ , he thought, that Atsumu kissed him so tenderly after sex that it made Osamu feel lost, feel stupid in a way his dumb brother’s cock just couldn’t make him. He kissed back, holding Atsumu’s face with shaky digits, but his brother didn’t tease him for it.

It wasn’t uncommon to fall asleep like this, a mess of tangled limbs, wrapped together so tight half the bed was empty, even when the mattress was small on the bottom bunk.

And Osamu, curse his heart, wouldn’t have it any other way.

**Author's Note:**

> Follow me @ overexciteddrn I'm like, an artist, or something


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